System and method for forming connections with a compliant guide

ABSTRACT

A technique enables formation of connections between subsea well installations and compliant guides. The technique comprises deploying a compliant guide ( 22 ) from a surface vessel ( 26 ) toward a subsea well installation ( 24 ). A lower end of the compliant guide ( 22 ) is moved toward the sea floor in proximity to a subsea well installation. Subsequently, one or more submerged tools operate in cooperation with a lower end ( 32 ) of the compliant guide ( 22 ) to move the compliant guide ( 22 ) into engagement with the subsea well installation ( 24 ).

BACKGROUND

The production and transfer of fluids from subsea wells relies on subsea installations, surface vessels or structures, subsea flow lines and other equipment. In some applications, compliant guides are deployed between a surface vessel and a subsea installation. Difficulties arise in landing the compliant guide onto the subsea installation due, at least in part, to the motion of the surface vessel relative to the seabed.

The compliant guide can be directed by guide wires connected between the subsea installation and the surface vessel. At the surface vessel, the guide wires are connected to a wave motion compensating system. Other systems operate without guide wires run between the subsea installation and the surface vessel. For example, systems exist that detect the motion of the surface vessel via accelerometers. The information from the accelerometers is used by a control system that compensates for the surface vessel motion while attempting to land the equipment onto the subsea installation.

SUMMARY

In general, the present invention provides a technique for forming connections between a subsea well installation and a compliant guide, such as a spoolable compliant guide. The technique comprises deploying a compliant guide toward a subsea well installation. Subsequently, one or more submerged tools operate in cooperation with a lower end of the compliant guide to land or otherwise move the compliant guide into engagement with the subsea well installation.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:

FIG. 1 is a schematic front elevation view of a compliant guide system coupled between a surface vessel and a subsea well installation, according to an embodiment of the present invention;

FIG. 2 is a schematic front elevation view of the compliant guide being moved into engagement with a subsea well installation by connection formation equipment, according to an embodiment of the present invention;

FIG. 3 is a schematic front elevation view of the compliant guide being moved into engagement with a subsea well installation by connection formation equipment, according to an alternate embodiment of the present invention;

FIG. 4 is a schematic front elevation view of the compliant guide being moved into engagement with a subsea well installation by connection formation equipment, according to an alternate embodiment of the present invention;

FIG. 5 is a schematic front elevation view of the compliant guide being moved into engagement with a subsea well installation by connection formation equipment, according to an alternate embodiment of the present invention;

FIG. 6 is a schematic front elevation view of the compliant guide being moved into engagement with a subsea well installation by connection formation equipment, according to an alternate embodiment of the present invention;

FIG. 7 is a schematic front elevation view of the compliant guide being moved into engagement with a subsea well installation by connection formation equipment, according to an alternate embodiment of the present invention;

FIG. 8 is a schematic front elevation view of the compliant guide being moved into engagement with a subsea well installation by connection formation equipment, according to an alternate embodiment of the present invention;

FIG. 9 is a schematic front elevation view of the compliant guide being moved into engagement with a subsea well installation by connection formation equipment, according to an alternate embodiment of the present invention;

FIG. 10 is a schematic front elevation view of the compliant guide being moved into engagement with a subsea well installation by connection formation equipment, according to an alternate embodiment of the present invention;

FIG. 11 is a schematic front elevation view of the compliant guide being moved into engagement with a subsea well installation by connection formation equipment, according to an alternate embodiment of the present invention; and

FIG. 12 is a schematic front elevation view of the compliant guide being moved into engagement with a subsea well installation by connection formation equipment, according to an alternate embodiment of the present invention.

DETAILED DESCRIPTION

In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.

The present invention generally relates to a technique for utilizing a compliant guide system, such as a spoolable compliant guide system, connected between a surface vessel and a subsea well installation. The technique utilizes one or more connection systems and methodologies that facilitate engagement of the compliant guide with the subsea installation. In some applications, for example, the connection systems and methodologies can be utilized in facilitating the connection of the lower end of a spoolable compliant guide with a corresponding connector of a lubricator on the subsea well installation.

In deploying a spoolable compliant guide, the guide can be fully deployed into its compliant shape such that the lower end of the guide is at a shallower depth relative to a corresponding connector of the subsea well installation. The various connection techniques described below are used to move the lower, connector end of the spoolable compliant guide into proximity and engagement with the subsea well installation. The connector techniques can be utilized in creating a downward force strong enough to overcome the buoyancy of the compliant guide which naturally tends to bias the lower end of the compliant guide away from the subsea well installation. This biasing force can be useful, however, during various emergency disconnect procedures in which it is beneficial to separate the compliant guide from the subsea well installation.

Referring generally to FIG. 1, a well system 20 is illustrated according to an embodiment of the present invention. In this embodiment, well system 20 comprises a compliant guide 22, e.g. a spoolable compliant guide, coupled between a subsea well installation 24 and a surface vessel 26 located at a surface 28 of the sea. Subsea well installation 24 may be located on or at a seabed 30.

In the embodiment illustrated, compliant guide 22 is flexible and may be arranged in a variety of curvilinear shapes extending between a surface location, e.g. intervention vessel 26, and subsea well installation 24. This flexibility allows the compliant guide 22 to be arranged in a variety of compliant configurations, as desired, to facilitate deployment or retraction of tool strings. By way of example, compliant guide 22 may be constructed as a tubular member formed from a variety of materials that are sufficiently flexible, including metal materials of appropriate cross-section and composite materials. Regardless, compliant guide 22 comprises a connector end 32 by which the compliant guide is connected to the subsea well installation 24.

Although a variety of subsea installations 24 can be utilized depending on the particular environment and type of intervention operation or other well operation, one example is illustrated in FIG. 1. In this example, the subsea installation 24 comprises a subsea wellhead 34, such as a Christmas tree style wellhead, coupled to a subsea well 36. The subsea installation 24 also comprises a corresponding connector end 38 onto which connector end 32 is landed or otherwise engaged. By way of example, corresponding connector end 38 may be positioned at the upper end of a lubricator 40.

Subsea well installation 24 also may comprise a variety of other features and components. For example, subsea well installation 24 may comprise a subsea lubricating seal 42 deployed directly above subsea wellhead 34. Lubricating seal 42 can be used to close the borehole of subsea well 36 during, for example, intervention procedures. Additionally, a blowout preventer 44 can be located in subsea well installation 24 above subsea lubricating seal 42. Blowout preventer 44 may comprise one or more cut-and-seal rams able to cut the conveyance and seal off the subsea installation during an emergency disconnect. Other components, such as a subsea stripper assembly 46, also can be included in subsea well installation 24. Depending on the application, subsea well installation 24 may incorporate emergency disconnect devices and other components to enable its desired function.

The compliant guide 22 also can be used in cooperation with a variety of additional or alternate components that facilitate deployment of the compliant guide, use of the compliant guide, and protection of the subsea well in various subsea operations. For example, an emergency disconnect 48 can be provided at surface vessel 26 proximate an upper end 50 of compliant guide 22. Additionally, a clump weight 52 can be attached to a lower and 54 of compliant guide 22 to facilitate deployment of the compliant guide. Clump weight 52 is attached to lower end 54 by a tether 56 connected across a float 58 and provides weight to help overcome the buoyancy of compliant guide 22. During deployment, clump weight 52 draws the lower end of compliant guide 22 downwardly toward seabed 30 in an area proximate to subsea well installation 24. Connection systems also can be utilized with compliant guide 22 to facilitate engagement of the compliant guide with subsea well installation 24, as discussed in greater detail below.

Referring generally to FIG. 2, one embodiment of a connection system 60 is illustrated. Connection system 60 is used to facilitate the engagement, e.g. landing, of compliant guide 22, e.g. a spoolable compliant guide, onto subsea installation 24. In the specific embodiment illustrated, connector end 32 of spoolable compliant guide 22 is brought into engagement with corresponding connector end 38 of subsea well installation 24, e.g. a subsea lower intervention package. As illustrated, connection system 60 comprises a plurality of subsea winches 62 mounted to subsea well installation 24. Each subsea winch 62 comprises a winch cable 64 that extends upwardly through a cable guide 66 and into engagement with connector end 32. Each cable guide 66 is mounted on subsea installation 24 at a suitable location, such as corresponding connector end 38.

A remotely operated vehicle 68 is used to pick up the cables 64 from the winches 62 after clump weight 52 has been used to draw connector end 32 into proximity with subsea well installation 24. The remotely operated vehicle 68 is then operated so as to connect these cables to the spoolable compliant guide 22. Once the winch cables 64 are connected to spoolable compliant guide 22, the subsea winches 62 are activated to draw in the winch cables and to move connector end 32 into engagement with corresponding connector end 38. The subsea winches 62 can be activated electrically, hydraulically or by other suitable power sources. By way of example, the subsea winches 62 are activated by hydraulic power supplied through remotely operated vehicle 68 or through the subsea installation 24 via an appropriate control umbilical 70.

In the specific embodiment illustrated in FIG. 2, a pair of subsea winches 62 are used to draw connector end 32 into engagement with corresponding connector end 38. However, a single subsea winch 62 can be mounted to subsea well installation 24 and used to draw the spoolable compliant guide 22 into engagement with subsea well installation 24, as illustrated in FIG. 3. In the embodiment illustrated in FIG. 3, subsea winch 62 comprises a hydraulic wire spooling head 72 actuated by remotely operated vehicle 68 to induce pulling of winch cable 64, thereby drawing connector end 32 into engagement with corresponding connector end 38.

One or more subsea winches 62 can be deployed in a variety of locations depending on the environment and/or the configuration of subsea well installation 24, connection system 60, and compliant guide 22. For example, one or more subsea winches 62 can be mounted independently of subsea well installation 24. As illustrated in FIG. 4, subsea winches 62 are mounted on seabed 30. In this latter embodiment, remotely operated vehicle 68 is used to connect the one or more winch cables 64 to compliant guide 22 via, for example, connector end 32. The subsea winches 62 are then activated via a suitable power supply, e.g. pressurized hydraulic fluid, provided by remotely operated vehicle 68 or subsea well installation 24.

Another embodiment of connection system 60 is illustrated in FIG. 5. In this embodiment, connector end 32 of compliant guide 22 is moved toward corresponding connector end 38 of subsea well installation 24 by directing a discharge of fluid, as represented by arrows 74. The discharge of fluid is created by a jet assembly 76 having jets 78 through which the discharged fluid 74 is directed. After deploying compliant guide 22 into proximity with subsea well installation 24 via clump weight 52, fluid is pumped down through the interior of compliant guide 22, as represented by arrows 80. The fluid is then directed into generally arcuate or u-shaped passages 82 which change the direction of fluid flow before the fluid is discharged through jets 78.

To move connector end 32 into engagement with corresponding connector end 38, the discharge of fluid is directed upwardly, as illustrated in FIG. 5. However, jet assembly 76 may be rotatably or otherwise movably mounted on compliant guide 22 to enable adjustment of the discharge direction via, for example, remotely operated vehicle 68. By adjusting the direction of discharge, jet assembly 76 can be used to separate connector end 32 and corresponding connector end 38 during a disconnection procedure. Additionally, the jet assembly 76 can be rotated to change the direction of the fluid discharge for adjusting the horizontal position of connector end 32 relative to connector end 38.

The discharge of fluid 74 also can be induced by a propeller assembly 84, as illustrated in FIG. 6. In this embodiment, the discharge of fluid is induced by propellers 86 of propeller assembly 84. After deploying compliant guide 22 into proximity with subsea well installation 24, fluid is pumped down through the interior of compliant guide 22, as represented by arrows 80. The fluid is then directed into propeller assembly 84 to induce rotation of propellers 86. Propellers 86, in turn, provide the discharge of fluid that can be used to move connector end 32 of compliant guide 22.

As with the embodiment illustrated in FIG. 5, remotely operated vehicle 68 can be used to orient the direction along which fluid is discharged. Thus, propeller assembly 84 can be rotated by remotely operated vehicle 68 to selectively move connector end 32 in a downward direction for connection or in an upward direction for disconnection. Additionally, remotely operated vehicle 68 also can be used to assist in guiding compliant guide 22 down toward corresponding connector end 38 of subsea well installation 24. In some applications, remotely operated vehicle 68 is used to turn off flow to propellers 86 or to close off jets 78 via jet isolation valves. As an alternative, the remotely operated vehicle 68 is employed to supply fluid flow in addition or as an alternative to fluid flow 80 directed downwardly through the interior of compliant guide 22. In the embodiment of FIG. 7, for example, remotely operated vehicle 68 is connected to propeller assembly 84 by an appropriate control line able to provide a flow of fluid to propeller assembly 84 for driving propellers 86.

Referring generally to FIG. 8, another embodiment of connection system 60 is illustrated. In this embodiment, connection system 60 comprises a tensioning wire system 90 for drawing connector end 32 into engagement with corresponding connector end 38. Tensioning wire system 90 comprises a tensioning wire 92 mounted along compliant guide 22 in a manner able to guide the landing of compliant guide 22 onto subsea well installation 24.

Following placement of the subsea well installation 24 at seabed 30, compliant guide 22, e.g. a spoolable compliant guide, is deployed toward the subsea well installation 24 with the aid of clump weight 52. During deployment of compliant guide 22, tensioning wire 92 is positioned to extend through the connector end 32 of compliant guide 22 to a location below the connector end. The tensioning wire 92 is then clamped to compliant guide 22 by tension wire clamp 94 and guided through one or more tension wire guides 96 as compliant guide 22 is deployed. The upper portion of tensioning wire 92 is spooled onto a wire tensioning assembly 98 able to selectively spool or unspool tensioning wire 92. Once connected to wire tensioning assembly 98, tension is placed on tensioning wire 92 until the spoolable compliant guide 22 is moved into a desired compliant shape.

Subsequently, continued deployment of compliant guide 22 moves the compliant guide toward subsea well installation 24. When connector end 32 is generally proximate to subsea well installation 24, tensioning wire 92 is connected to subsea well installation 24 by remotely operated vehicle 68. After connecting the tensioning wire 92, the remotely operated vehicle 68 can again be used to loosen tension wire clamp 94 so that the stored energy in compliant guide 22 biases the compliant guide to a straighter shape. As a result, connector end 32 of compliant guide 22 is forced downwardly along tensioning wire 92 toward corresponding connector end 38 until a connection is made. Once connector end 32 and corresponding connector end 38 are engaged, the remotely operated vehicle 68 can be used to again tighten tension wire clamp 94. Disconnection of the compliant guide 22 from subsea well installation 24 can be achieved by reversing the procedure.

In other applications, the remotely operated vehicle 68 is used directly in moving the compliant guide 22 into engagement with subsea well installation 24. As illustrated in FIG. 9, once compliant guide 22 is deployed into proximity with subsea well installation 24, remotely operated vehicle 68 is attached or anchored to the lower end of compliant guide 22 by an appropriate handle 100. After attachment, remotely operated vehicle 68 can be operated to guide connector end 32 along both horizontal and vertical planes to properly position compliant guide 22 for engagement with subsea well installation 24. This technique is useful, for example, in applications utilizing a spoolable compliant guide that is not excessively stiff or subject to excessive motion.

Operation of the remotely operated vehicle 68 also can be assisted by a variety of cooperating mechanisms. For example, remotely operated vehicle 68 can be aided by a winch 102 connected between subsea well installation 24 and the remotely operated vehicle, as illustrated in FIG. 10. In the embodiment illustrated, winch 102 is mounted to remotely operated vehicle 68 and comprises a cable that extends to and is connected with corresponding connector end 38. By way of example, winch 102 may be a hydraulically operated winch operated by remotely operated vehicle 68. Thus, winch 102 is able to assist remotely operated vehicle 68 draw connector end 32 into engagement with corresponding connector end 38.

In another example, remotely operated vehicle 68 is aided by a hydraulic cylinder 104 connected between subsea well installation 24 and the remotely operated vehicle, as illustrated in FIG. 11. In this embodiment, hydraulic cylinder 104 comprises a cylinder and piston arrangement which cooperate to selectively expand and contract the length of the hydraulic cylinder upon the appropriate hydraulic input from remotely operated vehicle 68. Hydraulic cylinder 104 is mounted between remotely operated vehicle 68 and corresponding connector end 38. Thus, the hydraulic cylinder 104 can be selectively actuated to assist remotely operated vehicle 68 draw connector end 32 into engagement with corresponding connector end 38.

Another embodiment of connection system 60 is illustrated in FIG. 12. In this embodiment, connector end 32 of compliant guide 22 is moved toward corresponding connector end 38 of subsea well installation 24 with the assistance of a controlled buoyancy module 106. The controlled buoyancy module 106 is installed at a lower end of compliant guide 22, and the actual buoyancy of module 106 can be controlled by remotely operated vehicle 68 via a fluid line 108. Fluid line 108 is used to add or remove a selected fluid able to change the buoyancy of controlled buoyancy module 106. Following deployment of compliant guide 22 into proximity with subsea well installation 24 via, for example, clump weight 52, the remotely operated vehicle 68 is engaged with a lower portion of compliant guide 22, e.g. connector end 32, via handle 100. In this embodiment, the remotely operated vehicle 68 is used to guide connector end 32 in a horizontal plane while controlling the buoyancy of module 106 to appropriately move connector end 32 along a vertical plane until engaged with corresponding connector end 38. The controlled buoyancy module 106 also can be used to facilitate disconnection of compliant guide 22 from subsea well installation 24.

Connection system 60 is used to facilitate engagement of compliant guides, e.g. spoolable compliant guides, with a variety of subsea well installations that can be used for intervention procedures or other procedures. The overall well system 20 and connection system 60 also can incorporate a variety of additional or alternate components depending on the specific environment and procedure undertaken. Additionally, one or more remotely operated vehicles can be utilized in connecting and disconnecting many types of components at the subsea location. The connection system and procedures also can be used with a compliant guides extending downwardly from many types of surface vessels and surface structures.

Although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this invention.

The present invention provides a method of connecting a compliant guide at a subsea location, comprising:

-   -   deploying a compliant guide toward a subsea well installation;     -   mounting a winch proximate the subsea well installation;     -   coupling a cable between the winch and a lower end of the         compliant guide; and     -   pulling the cable with the winch to draw the lower end into         engagement with the subsea well installation.

Preferably, said deploying step comprises deploying a spoolable compliant guide. Also, the deploying may comprise utilizing a clump weight to pull the spoolable compliant guide toward a seabed. The mounting step may comprise mounting a plurality of winches proximate the subsea well installation. The winch may be mounted on the subsea well installation or on a seabed. Coupling may comprise using a remotely operated vehicle to pick up the cable from the winch and to attach the cable to the lower end of the spoolable compliant guide. Pulling may comprise operating the winch via hydraulic power.

In another embodiment of the present invention a method is provided which comprises:

-   -   deploying a compliant guide toward a subsea well installation;     -   moving a connector end of the compliant guide toward a         corresponding connector end of the subsea well installation by         directing a discharge of fluid; and     -   connecting the connector end and the corresponding connector         end.

Deploying may comprise deploying a spoolable compliant guide and/or utilizing a clump weight to pull the spoolable compliant guide toward a seabed. Moving may comprise directing a flow of fluid downwardly through the spoolable compliant guide and out through a directional jet assembly to create the discharge of fluid. Alternatively, moving may comprise directing a flow of fluid downwardly through the spoolable compliant guide to power a propeller used to direct the discharge of fluid. Moving may also comprise operating a remotely operated vehicle to power a propeller to create the discharge of fluid. A remotely operated vehicle may be used to change the direction in which fluid is discharged.

The inventive method may also comprise: disconnecting the connector end from the corresponding connector end; and changing the direction along which the fluid is discharged to move the connector end away from the corresponding connector end.

Yet another embodiment of the present invention provides a method, comprising:

connecting to tensioning wire along a compliant guide;

deploying the compliant guide toward a subsea well installation;

connecting the tensioning wire to the subsea installation; and

using the tensioning wire to guide a lower connector end of the compliant guide into engagement with the subsea well installation.

The tensioning wire may be connected to a spoolable compliant guide. The tensioning wire may be connected so a lower end of the tensioning wire extends below the spoolable compliant guide. Said connecting step may further comprise temporarily clamping the tensioning wire to the spoolable compliant guide via a tension wire clamp and tensioning the tensioning wire to cause the spoolable compliant guide to move into a compliant shape. Using the tensioning wire comprises releasing the tension wire clamp so the spoolable compliant guide straightens and moves the connector end toward the subsea well installation. Releasing may comprise using a remotely operated vehicle to release the tension wire clamp. The tensioning wire may be clamped at the tension wire clamp after engagement of the lower connector with the subsea well installation. The method as recited in claim 18, wherein connecting comprises using a remotely operated vehicle to connect the tensioning wire to the subsea well installation.

Yet another embodiment of the present invention comprises:

-   -   deploying a compliant guide toward a subsea well installation;     -   coupling a remotely operated vehicle proximate a connector end         of the compliant guide; and     -   operating the remotely operated vehicle to move the connector         end into alignment with the subsea installation for connection         of the connector end with the subsea installation.

Deploying may comprise deploying a spoolable compliant guide. Also the method may further comprise assisting the remotely operated vehicle with a winch actuated by the remotely operated vehicle, the winch being connected between the subsea well installation and the remotely operated vehicle. The method further may comprise assisting the remotely operated vehicle with a cylinder actuated by the remotely operated vehicle, the cylinder being connected between the subsea well installation and the remotely operated vehicle. Alternatively, assisting the remotely operated vehicle with a controlled buoyancy module able to move the connector end vertically may also be used. 

1. A method of connecting a compliant guide at a subsea location, comprising: deploying a compliant guide toward a subsea installation; mounting a winch proximate the subsea well installation; coupling a cable between the winch and a lower end of the compliant guide; and pulling the cable with the winch to draw the lower end into engagement with the subsea well installation.
 2. The method as recited in claim 1, wherein said compliant guide is a spoolable compliant guide.
 3. The method as recited in claim 1, wherein said deploying step further comprises utilizing a clump weight to pull the spoolable compliant guide toward a seabed.
 4. The method as recited in claim 1, wherein said mounting step may further comprise mounting a plurality of winches proximate the subsea well installation.
 5. The method as recited in claim 1, wherein said coupling includes using a remotely operated vehicle to pick up the cable from the winch and attaching the cable to a lower end of compliant guide.
 6. The method as recited in claim 1, wherein said pulling further comprises operating the winch via hydraulic power.
 7. A method of connecting a compliant guide at a subsea location, comprising: deploying a compliant guide toward a subsea installation; moving a connector end of the compliant guide toward a corresponding connector end of the subsea well installation by directing a discharge of fluid; connecting the connector end of the compliant guide to the corresponding connector end of the subsea well installation.
 8. The method as recited in claim 7, wherein said compliant guide is a spoolable compliant guide.
 9. The method as recited in claim 7, wherein said deploying step further comprises utilizing a clump weight to pull the compliant guide toward a seabed.
 10. The method as recited in claim 7, wherein said moving further comprises directing a flow of fluid downwardly through the compliant guide and out through a directional jet assembly to create the discharge of fluid.
 11. The method as recited in claim 7, wherein said moving further comprises directing a flow of fluid downwardly through the compliant guide to power a propeller used to direct the discharge of fluid.
 12. The method as recited in claim 7, wherein said moving further comprises operating a remotely operated vehicle to power a propeller to create the discharge of fluid.
 13. A method of connecting a compliant guide at a subsea location, comprising: deploying a compliant guide toward a subsea installation; connecting a tensioning wire along a compliant guide; connecting the tensioning wire to the subsea installation; and using the tensioning wire to guide a lower connector end of the compliant guide into engagement with the subsea well installation.
 14. The method as recited in claim 13, wherein said compliant guide is a spoolable compliant guide.
 15. The method as recited in claim 13, wherein said tensioning wire is connected to the guide in a way so that a lower end of the tensioning wire extends below the spoolable compliant guide.
 16. The method as recited in claim 13, wherein said connecting to the guide further comprises temporarily clamping the tensioning wire to the guide via a tension wire clamp and tensioning the tensioning wire to cause the guide to move into a compliant shape.
 17. The method as recited in claim 13, further comprising using the tensioning wire to release the tension wire clamp so that the guide straightens and moves the connector end toward the subsea well installation. 